Va Tech Extension weighs in on the Cicada invasion
Here is the VTCE read on the Cicadas. BV took the photos in Daleville yesterday of the various stages of the life cycle. Anyone know what the red beetles are feasting on a shed shell of the Cicada?
17 year Cicadas in Botetourt
Get ready folks: it is Botetourt’s turn for the 17-year cicadas. Periodical cicadas are also known as the “17-year cicada”, “13-year cicada”, or “locust”. Locust is somewhat misleading because it also applies to migratory grasshoppers.
Most people are familiar with the dog day cicada that is prevalent annually in midsummer. The dog day cicada is a mottled, dark green color and can be distinguished from the periodical cicada, which is about 1 to 1 ½ inches long, black, with red eyes and orange legs. Adult periodical cicada’s have clear wings with distinctive orange veins. When viewed from the front, the wings form an inverted “V” and meet at the top like a roof. Immature cicadas are wingless, pale white to tan with a bulbous head and well-developed legs. Because they spend their entire life underground, they are rarely collected or observed.
In Virginia both the 17 and the 13-year cicadas damage many ornamental and hardwood trees. Oaks are commonly attacked, but the most seriously damaged are newly planted fruit and ornamental trees. These include apple, dogwood, peach, hickory, cherry, and pear. Pines and others conifers are not commonly attacked.
Damage caused by nymphs feeding on the plant roots is considered very minor. The adults do not feed on the upper portions of the tree after they emerge, but the egg laying of female cicadas causes significant damage to small twigs. The female places her saw-like egg laying tube, called an ovipositor, into small branches and twigs that are about the diameter of a pencil. Twigs will die because the branch is split when the eggs are placed under the thin bark. This dead twig contrast with the surrounding green foliage results in a condition called “flagging.” Young trees are the most severely damaged by flagging because they have more branches of the preferred size for egg laying. Large, established trees can often have high amounts of flagging, but rarely suffer severe damage.
Avoid planting new fruit and ornamental trees in the same year as a predicted cicada emergence. Newly planted trees can be covered with fine netting to keep the cicadas from reaching the small, tender twigs. Secure the netting around the trunk to stop them from climbing up into the tree. Remove the netting at the end of June. Remove flagging damage and destroy the snippings to reduce the number of nymphs that will establish on the roots of that tree. Spraying will give limited control, as new cicadas will fly in to replace the individuals killed by the spray.
Immature cicadas (nymphs) do not feed on the twig where they hatch but drop to the ground and burrow to the root system below the tree. Once attached, they stay on the root for 13 or 17 years or until the next emergence.
Cicadas are not poisonous and do not have a stinger. Communities and farms with large numbers of cicadas emerging from the ground often are beset with a substantial noise problem. Half of the cicada population is males “singing” or calling for the females. The annoyance from the singing is tempered by the fact that the periodical cicadas are only out for a single four to six week period every 17 years, but they can occur more frequently when broods overlap.
The common name 13 and 17-year cicada applies to the developmental period required for the nymphs to reach adulthood. Adults start appearing in Virginia in early May, with numbers peaking in early June. Numbers decline by late June, and most cicadas are gone by July. In most of Virginia, periodical cicadas emerge in specific locations once every 17 years. In some of the southern counties, there are periodical cicadas that emerge once every 13 years. There are seventeen broods of the 17-year cicada and thirteen broods of the 13-year cicada. Every year, they emerge somewhere in the state. Some counties have several broods in different locations.
Submitted by Kate Lawrence; Photos by Cathy Benson



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